This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from my application entitled INK CARTRIDGE FOR INK JET PRINTER filed with the Korean Industrial Property Office on Nov. 6, 2000 and there duly assigned Serial No. 00-65519.
1. Field of the Invention
The present invention relates to an ink cartridge used for an ink jet printer. In particular, this invention provides an apparatus and a method of using an ink cartridge that efficiently consumes nearly all the ink that is emptied into the cartridge. Furthermore, an automatic sensing means is disclosed to electrically determine when the ink cartridge needs to be refilled.
2. Description of the Related Art
In general, an ink cartridge for an ink jet printer containing ink ejects droplets of ink from a head to print an image of a predetermined color on a sheet of paper. However, ink jet printers contain a sponge within the ink cartridge to hold and dispense the ink. Unfortunately since the sponge takes up nearly all the space inside the cartridge, the cartridge will have to be replaced even when there is a substantial amount of ink left in the sponge. This is wasteful. Also, ink cartridges contain no means for allowing the user to know when the cartridge has to be replaced.
It is therefore an object of the present invention to provide an improved ink cartridge.
It is also an object of the present invention to provide an ink cartridge for an ink jet printer which can improve the efficiency in use of stored ink while preventing a wetting phenomenon.
It is further an object of the present invention to provide an electrical sensor to alert the user when the ink cartridge is empty.
It is still yet another object of the present invention to provide a mechanism that continuously maintains negative pressure (or a pressure below atmospheric pressure) inside the ink cartridge until all the ink inside the ink cartridge is consumed.
Accordingly, to achieve the above object, there is provided an ink cartridge for an ink jet printer having an ink storing portion for containing ink and a head for ejecting droplets of the ink stored in the ink storing portion, wherein the ink storing portion comprises a chamber filed with ink in a liquid state, a negative pressure maintaining means for maintaining the pressure of the inside of the chamber to be negative, and a uniform supply guide means, installed between the chamber and the head, for guiding the ink in the chamber to be uniformly supplied to the head.